half2full.swift

//
//  main.swift
//  half2full
//
//  Created by eien.support@gmail.com on 2017/08/02.
//  Copyright © 2017年 Eien Factory. All rights reserved.
//

import Foundation

func fileHandle(path:String) -> NSFileHandle? {
    let url = NSURL(fileURLWithPath: path)
    return NSFileHandle(forReadingAtPath: url.path!)
}

let args = Process.arguments
var inputHandle: NSFileHandle?
var toFull = true
for i in 1..<args.count {
    let arg = args[i]
    if arg == "-r" {
        toFull = false
        continue
    }
    if arg.hasPrefix("-") {
        continue
    }
    if arg.hasPrefix("+") {
        continue
    }
    inputHandle = fileHandle(arg)
    if inputHandle != nil {
        break
    }
}

let standardInput = inputHandle ?? NSFileHandle.fileHandleWithStandardInput()
let standardOut = NSFileHandle.fileHandleWithStandardOutput()
while true {
    let input = standardInput.availableData
    if input.length == 0 { break }
    let dataString = NSString(data:input, encoding:NSUTF8StringEncoding)
    let str = dataString?.mutableCopy() as! NSMutableString
    CFStringTransform(str, nil, kCFStringTransformFullwidthHalfwidth, toFull)
    if let out = str.dataUsingEncoding(NSUTF8StringEncoding) {
        standardOut.writeData(out)
    }
}
standardOut.writeData(NSString(string: "\n").dataUsingEncoding(NSUTF8StringEncoding)!)